The present invention relates generally to the field of portable lifting devices and, more particularly, to a demountable lifting device with a wide variety of selectable configurations.
As the number of packages carried between locations increases, the need for more effective lifting devices increases. In most cases, robust deliverymen move heavy objects by physically lifting them from a storage location and placing them on a conventional transport device, such as a dolly or hand truck. For example, a delivery person might lift an object, such as a computer or printer, from a delivery truck and use a dolly to transport the object inside an office. Once inside the office, the delivery person again physically lifts the object and installs it in the desired location. Although many objects and can be physically manipulated in the manner, this technique has its limits, and can lead to serious consequences. For example, the availability of candidates to fill the delivery person job may be limited in instances in which only significantly robust individuals have the requisite strength to physically move the objects to be delivered. In some cases, this might require two delivery persons to deliver an object, when one delivery person with a more effective lifting device might be able to do the job. And even for strapping individuals, repetitive unaided lifting can result in injuries. In this long run, these injuries increase employment and insurance costs.
Mechanical lifting devices have been developed to assist in lifting certain types of objects. However, many of these devices are specialized for lifting only certain types of object and, as a result, do not provide a versatile or universal solution. Even lifting devices intended for general use typically do not adjust to accommodate objects of widely varying dimensions. In addition, many conventional lifting devices are not designed to facilitate portability, which further impedes their usefulness for certain applications. For example, many trucks are equipped with hydraulic lifts, but the lift cannot be removed for use in areas where the truck cannot travel. Many delivery trucks also carry a conventional hand truck, which can be removed for on-site use. But the hand truck does not include a power-assisted lifting device. In addition, portable power-assisted lifting devices have been developed, but these devices typically lack adjustments for enhancing portability or accommodating objects of widely varying dimensions.
Thus, there is a need for portable lifting devices with adjustments for enhancing portability or accommodating objects of widely varying dimensions.
The present invention meets the needs described above in a portable, power-assisted lifting device that can be quickly and easily taken apart and reassembled. In particular, the lifting device includes a mast constructed from two or more separable sections and a lifting belt, which can be any suitable type of flexible connector, such as a strap, chain, cable or other suitable connector, that can be supported by, or removed from, the mast. For example, the lifting belt typically extends over the top of the mast, and can be removed from this position to allow the mast to be easily taken apart. This allows the length of the mast to be adjusted to accommodate objects of widely varying dimensions.
The lifting device may include a removable carriage, which can be driven up and down the mast by the lifting belt. The lifting device may also include a drive mechanism for moving the carriage up and the mast, by reeling the lifting belt in or out. For example, the drive mechanism may be a crank driven by hand. Alternatively, the crank may be driven by a motor, such as a battery-powered electric drill or other suitable device. In addition, the gear box for the belt reel may include a fitting that may alternatively receive the hand crank or the battery-powered electric drill.
The removable carriage may carry various types of selectively removable end effectors to accommodate lifting different types of objects. For example, certain end effectors may be fixed, while others may be adjustable. In some cases, the end effectors may be driven (e.g., opened, closed, rotated, etc.) by a hand or motorized device, such as the same device that drives the carriage up and down the mast. Different types of removable carriages may also be deployed.
The ability to easily take apart and reassemble the lifting device, which is referred to as xe2x80x9cdemountability,xe2x80x9d enables efficient storage when the device is not in use. For example, the disassembled lifting device could be stored in a rack mounted on a delivery truck or equipment bay. The storage rack may include an electric cradle to charge the battery in the battery-powered electric lift and propulsion motors while the lifting device is in storage. From this storage position, many different configurations of the lifting device may be quickly assembled for many different applications.
Generally described, the invention is a lifting device that includes a mast separable into a plurality of sections and a pulley supported by a first section of the mast. A dolly that supports the mast includes one or more transport structures for movably supporting the lifting device. An actuator is mounted on a second section of the mast. A carriage captured on the mast is configured to slide along the mast and directly or indirectly support an object to be lifted. The invention also includes a belt with a first end and a second end. The first end attaches to the carriage and the second end attaches to the actuator so that the belt extends over the pulley. The actuator selectively reels the belt in and out when the belt is positioned over the pulley. This causes the carriage to move up and down along the mast. Because the belt is removable from the pulley, the first section of the mast may be removed from the second section of the mast when the belt is removed from the pulley. This provides the lift with demountable portability.
More specifically described, the dolly could include a first leg assembly and a second leg assembly that extend from the dolly. These assemblies support the lifting device and enhance mobility. Alternatively, the carriage could include at least two end effectors that directly support the object to be lifted. The actuator could also include a crank or a motor.
In view of the foregoing, it will be appreciated that the lifting device of the present invention avoids the drawbacks of prior systems. The specific techniques and structures employed by the invention to improve over the drawbacks of the prior systems and accomplish the advantages described above will become apparent from the following detailed description of the embodiments of the invention and the appended drawings and claims.